US20080224162A1 - Light emitting diode package - Google Patents

Abstract

A light emitting diode (LED) package including: an LED chip; a first lead frame having a heat transfer unit with a top where a groove for stably mounting the LED chip is formed; a second lead frame disposed separately from the first lead frame; a package body having a concave portion encapsulating a portion of the heat transfer unit and the second lead frame but exposing a portion of the top of the heat transfer unit and a portion of the lead frame, and a ring-shaped portion extended in a ring shape along an inner wall of the groove of the heat transfer unit and forming an aperture in a center thereof; and a phosphor layer formed on the aperture of the ring-shaped portion and applied to the LED chip, wherein the LED chip is disposed in the inside of the aperture of the ring-shape portion.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims the priority of Korean Patent Application No. 2007-0025170 filed on Mar. 14, 2007, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a light emitting diode (LED) package, and more particularly, to an LED package not only having an excellent thermal emission properties and high durability but also with a small light loss and improved color uniformity.
• 2. Description of the Related Art
• Recently, light emitting diodes (LEDs) are generally used as a light source for lighting or a light source for a backlight unit for a liquid crystal display (LCD). Generally, an LED package such as a white LED device outputs light of a desired mixed color by converting a wavelength of light emitted from an LED chip by using phosphors disposed outside the LED chip. For example, a white LED package manufactured by applying yellow phosphors on a blue LED chip emits a white light by mixing a blue light and a yellow light obtained by converting by the phosphors.
• Since an LED package used for a light device or a large LCD device requires a white light or another mixed color light, with a great output and high quality, a package structure having an excellent thermal emission function and high color uniformity according to a far-field beam distribution is required. Also, to improve efficiency of an LED package, it is required to reduce a light loss due to light incapable of being emitted outside and returning to phosphors and a chip to be absorbed or distinguished.
• FIGS. 1A to 1C are cross-sectional views illustrating conventional LED packages.
• Referring toFIG. 1A, anLED package10 includeslead frames12aand12binserted therein, apackage body11 havingareflective cup11a,and anLED chip15 mounted on thereflective cup11a.Aresin encapsulation portion18 encapsulates theLED chip15 in thereflective cup11a.In theresin encapsulation portion18, phosphors including a mixture of phosphors for converting a color are scattered.
• According to the LED package ofFIG. 1A, color is nonuniform according to a far-field beam distribution due to a difference between a color conversion rate of a beam vertically emitted from a top surface of theLED chip15 caused by the phosphors and that of a beam emitted from a side of theLED chip15 caused by the phosphors. Accordingly, entire color uniformity becomes low and quality of an output light such as lighting quality is deteriorated. To obtain uniform color, an additional color mixing element may be mounted. However, this becomes a cause of increasing manufacturing costs. Also, since an insulating body is used for thepackage body11 and there is no additional heat slug structure, thermal emission properties required in a high power LED is bad.
• FIG. 1B illustrates a conventional package structure provided to improve color uniformity of an output light. Referring toFIG. 1B, anLED package20 includes apackage board24, anLED chip25 mounted on theboard24, aresin encapsulation element28 encapsulating theLED chip25. Aphosphor layer26 is disposed with a certain distance from theLED chip25. Since color is converted by thephosphor layer26, uniformity of emitted color may be improved. However, it is difficult to stably form a phosphor layer having the structure, and a process of manufacturing the LED package is complicate. Also, due to a low reproducibility of the manufacturing process, there are shown different light output characteristics for each product. Accordingly, due to great manufacturing dispersion, it is difficult to actually apply.
• AnLED package30 ofFIG. 1C includes anLED chip35 mounted on a reflective cup and aphosphor36 disposed around theLED chip35, which is capable of improving color uniformity. Through thephosphor layer36 with a certain thickness, formed on a top surface and side surfaces of theLED chip35, color uniformity of light outputted from anencapsulation element38 is capable of being improved. However, there is a great loss of light reflected by thephosphor layer36. In detail, since there are five surfaces where thephosphor layer36 is in contact with theencapsulation element38, that is, a top surface and four side surfaces, a considerable part of light emitted from theLED chip35, which is incapable of being out of the package30and is reflected to theLED chip35, is scattered inside thephosphor layer35 and distinguished, thereby causing a light loss of thepackage30. Also, to obtain a structure of thepackage30, a phosphor layer having a uniform thickness should be formed around an LED chip and it is required to reduce thickness dispersion between products, which requires a complicate manufacturing process and precise manufacturing conditions.
SUMMARY OF THE INVENTION
• An aspect of the present invention provides a light emitting diode (LED) package having high color uniformity according to a view angle, less light loss, and excellent thermal emission characteristics.
• According to an aspect of the present invention, there is provided an LED package including: an LED chip; a first lead frame having a heat transfer unit with a top where a groove for stably mounting the LED chip is formed; a second lead frame disposed separately from the first lead frame; a package body having a concave portion encapsulating a portion of the heat transfer unit and the second lead frame but exposing a portion of the top of the heat transfer unit and a portion of the lead frame, and a ring-shaped portion extended in a ring shape along an inner wall of the groove of the heat transfer unit and forming an aperture in a center thereof; and a phosphor layer formed on the aperture of the ring-shaped portion and applied to the LED chip, wherein the LED chip is disposed in the inside of the aperture of the ring-shape portion.
• The heat transfer unit may be formed by folding a sheet metal two times or more. In this case, the sheet metal with a top may have a hole to form the groove of the heat transfer unit. Also, the top of the folded sheet metal may have a ring-shape since an incised portion connected to the hole is formed thereon.
• The heat transfer unit may be formed of a sheet metal lamination body where two or more sheet metals are laminated. In this case, an uppermost sheet metal of the sheet metal lamination body may have a hole to form the groove of the heat transfer unit. The uppermost sheet metal may have a ring shape since an incised portion connected to the hole is formed thereon.
• The heat transfer unit may be formed of a single structure of a sheet metal consecutively extended in a thickness direction. In this case, the sheet metal may have different thicknesses in an inner area and an outer area of the groove of the heat transfer unit.
• At least a portion of a bottom of the heat transfer unit may be exposed from a bottom of the package body. An inner wall of the ring-shaped portion may be slant in such a way that the aperture has a top broader than a bottom thereof. A height of the aperture of the ring-shaped portion may be 0.1 to 0.7 mm. A horizontal distance between the inner wall of the ring-shaped portion and the LED chip may be from 0.2 to 0.5 mm.
• The LED package may further include a light-transmitting encapsulation portion formed in the concave portion of the package body and covering a top surface of the phosphor layer. The light-transmitting encapsulation portion may contain a light diffuser. Also, the light-transmitting encapsulation portion may contain phosphors.
• The LED package may further include a lens mounted on the light-transmitting encapsulation portion. The lens may have various forms such as a hemisphere, a dome, and an oval. Also, the light-transmitting encapsulation portion may be formed in the shape of a lens. The top surface of the phosphor layer may have a shape of one of a convex lens and a concave lens.
• The LED package may further include a submount mounted on a bottom of groove and having electrode patterns. The LED chip may be mounted on the submount and electrically connected to the electrode patterns. The electrode patterns of the submount may be electrically connected to the lead frame by bonding wires.
• A hole for indicating a polarity may be formed on one of external terminals of the first and second lead frames exposed from the package body.
BRIEF DESCRIPTION OF THE DRAWINGS
• The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
• FIGS. 1A to 1C are cross-sectional views illustrating conventional light emitting diode (LED) packages;
• FIG. 2 is a perspective view illustrating an LED package according to an exemplary embodiment of the present invention;
• FIG. 3 is a top view illustrating the LED package ofFIG. 2;
• FIG. 4 is a cross-sectional view illustrating the LED package ofFIG. 2, cut along a line AA′;
• FIG. 5 is a cross-sectional view illustrating the LED package ofFIG. 2, cut along a line BB′;
• FIG. 6 is a bottom view illustrating the LED package ofFIG. 2;
• FIG. 7 is a cross-sectional view illustrating an LED package according to another embodiment of the present invention, cut along the line BB′;
• FIG. 8 is a cross-sectional view illustrating an LED package according to still another embodiment of the present invention, cut along the line AA′;
• FIG. 9 is a cross-sectional view illustrating a path of reflective light in the LED package ofFIG. 2;
• FIGS. 10A to 11B are top views illustrating operations of a process of manufacturing an LED package, according to an exemplary embodiment of the present invention;
• FIGS. 12A to 12G are cross-sectional views illustrating the operations of the process of manufacturing an LED package; and
• FIGS. 13 to 17 are cross-sectional views illustrating LED packages according to embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity.
• FIG. 2 is a perspective view illustrating a light emitting diode (LED)package100 according to an exemplary embodiment of the present invention,FIG. 3 is a top view illustrating theLED package100,FIG. 4 is a cross-sectional view illustrating theLED package100 cut along a line AA′,FIG. 5 is a cross-sectional view illustrating theLED package100 cut along a line BB′, andFIG. 6 is a bottom view illustrating theLED package100.
• TheLED package100 includes first and second lead frames110 and120, separately disposed, apackage body130, anLED chip105, and aphosphor layer160. Thefirst lead frame110 has aheat transfer unit112 in the center of thepackage body130. Thepackage body130 encapsulates portions of the first and second lead frames110 and120, that is, the portions of the lead frames110 and120 are inserted into thepackage body130. TheLED chip105 is mounted on theheat transfer unit112, and thephosphor layer160 encapsulates theLED chip105. Thephosphor layer160 may be, for example, a transparent resin or polymer such as silicone and epoxy, which is filled with phosphors.
• Theheat transfer unit112 is formed of a top112aand a bottom112b,which forms a step. Agroove140 for stably mounting theLED chip105 is formed on the top112aas shown inFIGS. 4 and 5. Via theheat transfer unit112, heat generated by theLED chip105 is easily emitted, thereby minimizing a heat transfer path.
• As shown inFIG. 5, theheat transfer unit112 may be formed by folding a sheet metal two or more times. In this case, the top112aand the bottom112bformed of the folded sheet metal may be strongly bonded by a binder such as solder or by welding. A portion of the top112aof theheat transfer unit112 is extended from thepackage body130 to form anexternal lead terminal116 of thefirst lead frame110. A portion or more of a bottom surface of the bottom112bof theheat transfer unit112, as clearly shown inFIG. 6, is exposed outwardly, thereby improving a thermal emission effect by theheat transfer unit112.
• When theheat transfer unit112 is formed by folding the sheet metal, a hole may be formed on the top112ato form thegroove140 for stably mounting theLED chip105. Also, an incisedportion141 connected to the hole may be formed on the top112ato form the top112ain a ring shape (refer toFIGS. 3 and 10). As described below, a structure having one of an incised portion and a ring shape allows a ring-shaped portion to be easily formed.
• Thepackage body130 includes aconcave portion132 encapsulating portions of theheat transfer112 and thesecond lead frame120 and exposing the top112aof theheat transfer unit112 and another portion of thesecond lead frame120. A top of thepackage body130 forms areflective cup130aby theconcave portion132. An inner wall of theconcave portion132 is inclined in such a way that a top of theconcave portion132 is broader than a bottom thereof, which allows light emitted from light sources such as theLED chip105 and thephosphor layer160 to be reflected upward. Astep portion134 may be formed around the outside of theconcave portion132. Thestep portion134 may support and guide one of a cover or lens mounted on a light-transmitting encapsulation portion180 (refer toFIG. 13). Thepackage body130 supports thelead frame110 and120 and may be formed by in insertion molding or injection molding plastic or polymer.
• Also, thepackage body130 has a ring-shapedportion130bformed in thegroove140 of theheat transfer unit112. The ring-shapedportion130bforms a portion of thepackage body130 and is extended in the shape of a ring along an inner wall of the groove of theheat transfer unit112, where anaperture114 is formed in the center of the ring-shapedportion130b.The ring-shapedportion130ballows thefirst lead frame110 including theheat transfer unit112 and thesecond lead frame120 to be more strongly bonded with thepackage body130 and restrains a separation between elements such as the lead frames110 and120 and theheat transfer unit112 due to external impacts, thereby increasing mechanical durability of thepackage body130.
• TheLED chip105 is mounted in theaperture114 of the ring-shapedportion120 to be disposed on a bottom of thegroove140 of theheat transfer unit112, and thephosphor layer160 is formed on theaperture114 to coat theLED chip105. The mountedLED chip105 may be electrically connected to the lead frames110 and120 in many ways. For example, in the present embodiment, a bottom, an electrode, of theLED chip105 of a vertical type may be electrically connected to thefirst lead frame110 by soldering, a top, an electrode, of theLED chip105 may be electrically connected to thesecond lead frame120 by bonding wires W. On the other hand, in the case of theLED chip105 of a lateral type, an electric connection between theLED chip105 and the lead frames110 and120 may be performed by two bonding wires (refer toFIG. 16).
• A certain amount of a resin containing phosphors is dispensed into theaperture114 of the ring-shapedportion130b,thereby easily forming thephosphor layer160 with a relatively uniform thickness to coat theLED chip105 by the relatively uniform thickness. A height of the ring-shapedportion130bmay be from 0.1 to 0.7 mm from a top surface of theLED chip105, and a horizontal distance between an inner wall of the ring-shapedportion130band theLED chip105 may be from 0.2 to 0.5 mm. Thephosphor layer160 with a uniform thickness may be easily formed by determining a size of the ring-shapedportion130bwithin a range as described above.
• Particularly, the inner wall of the ring-shapedportion130bis inclined in such a way that light incident upon the inner wall of the aperture from theLED chip105 is easily reflected in an upper direction of theaperture114. An effect of a reflective cup may be obtained by using the inner wall of theaperture114 of the ring-shapedportion130b.
• The light-transmittingencapsulation portion180 is disposed in theconcave portion132 of thepackage body130 and covers a top surface of thephosphor layer160. The light-transmittingencapsulation portion180 may be formed of a light-transmitting resin or polymer such as a silicone resin and epoxy resin. Since the light-transmittingencapsulation portion180 contains one of a light scattering material and a light dispersion material, which may allow colors of light emitted from thephosphor layer160 to be mixed. Also, the light-transmittingencapsulation portion180 contains phosphors identical to or different from the phosphors in thephosphor layer160, thereby outputting a desired light. A refractive index or light-transmitting index of the light-transmittingencapsulation portion180 may be identical to or different from that of thephosphor layer160.
• As shown inFIGS. 2 and 3, to protect theLED chip105 from a high transient voltage such as an electrostatic voltage, a protective device such as aZener diode115 may be disposed in one of the lead frames110 and120 and electrically connected to another thereof. In this case, not to shield an emitted light or not to disturb a light emission index, theZener diode115 is disposed outside of theaperture114. Also, to easily distinguish a polarity of the first and second lead frames110 and120, a hole or a chamber for indicating a polarity may be formed on one ofexternal terminals116 and120bof the first and second lead frames110 and120, exposed from thepackage body130. In this case, theexternal terminals116 and120bof the lead frames110 and120 indicate portions of the lead frames110 and120, which are exposed from thepackage body130 and connected an external circuit. InFIG. 2, ahole50 is formed on theexternal terminal120bof thesecond lead frame120.
• According to the present embodiment, due to theheat transfer unit112 functioning as a heat slug, there are shown excellent heat emission characteristics. Theheat transfer unit112 forms a portion of thefirst lead frame110, in which theheat transfer unit112 is formed in a single structure with theexternal lead terminal116, thereby preventing a departure or a separation of theheat transfer unit112. The lead frames110 and120 are more strongly bonded to thepackage body130 by the ring-shapedportion130b,thereby improving durability of the entire package. In addition, thephosphor layer160 coating theLED chip105 is disposed in theaperture114 of the ring-shapedportion130b,thereby removing color nonuniformity according to a far-field beam distribution and improving the entire color uniformity. Also, across-section of thephosphor layer160 is formed in a lens profile, in the present embodiment, a profile of a convex lens, thereby adjusting light intensity and far-field beam distribution.
• Also, according to the present embodiment, an incident area of light reflected toward theLED chip105 instead of being emitted outwardly is reduced, thereby reducing a loss due to phosphors. Referring toFIG. 9, light reflected toward theLED chip105 instead of being emitted outwardly from the light-transmittingencapsulation portion180 passes through the light-transmittingencapsulation portion180 where a portion thereof is reflected by an inner wall of thereflective cup130aof thepackage body130 to be scattered and another portion thereof is incident on thephosphor layer160 to be lost. According to the configuration, light incident on thephosphor layer160 may be incident on thephosphor layer160 via only one surface such as a top surface (compare withFIG. 1C). Accordingly, the incident area of the light incident on thephosphor layer160 is reduced, thereby reducing the light loss due to thephosphor layer160.
• FIG. 7 is a cross-sectional view illustrating an LED package according to another embodiment of the present invention, cut along the line BB′, which corresponds toFIG. 5. Referring toFIG. 7, theheat transfer unit112 is formed by laminating two or moreseparated sheet metals112a′ and112b′, instead of folding the sheet metal. Thesheet metals112a′ and112b′ may be bonded by solder or welding. In this case, there may be a hole on an uppermost sheet metal112a′ to form thegroove140 of theheat transfer unit112. Also, an incise portion connected to the hole may be formed on theuppermost sheet metal112a′ to form theuppermost sheet metal112a′ in the shape of a ring (refer toFIG. 10). Other elements and functions thereof are as described above.
• FIG. 8 is a cross-sectional view illustrating an LED package according to still another embodiment of the present invention, cut along the line AA′, which corresponds toFIG. 4. Referring toFIG. 8, theheat transfer unit112 may be formed of a single structure of a sheet metal consecutively extended in a thickness direction instead of being formed by folding or laminating a sheet metal. Thegroove140 is formed on theheat transfer unit112 formed in the single structure by step forming. Accordingly, there are different thicknesses of the sheet metal in an inner area and outer area of thegroove140 of theheat transfer unit112. An incised portion of thegroove140, corresponding to the incisedportion141 of the top112a,may be formed. Other elements and functions thereof are as described above.
• Hereinafter, a process of manufacturing an LED package according to an exemplary embodiment of the present invention will be described. FIGS.FIGS. 10A to 11B are top views illustrating operations of a process of manufacturing an LED package, according to an exemplary embodiment of the present invention, andFIGS. 12A to 12G are cross-sectional views illustrating the operations of the process of manufacturing an LED package.
• As shown inFIG. 10A,sheet metals112′ and120 are prepared. Thesheet metal112′ includes twosheet metals112aand112b,aconnection portion112dthereof, anextended portion116 to be an external terminal, extended toward thesheet metal112a.To obtain thesheet metal112′ in a shape shown inFIG. 10A, one sheet is prepared (FIG. 12A) and required shapes such as ahole140′ and an incisedportion141 are formed on thesheet metal112aby punching (FIG. 12B). Accordingly, thesheet metal112ais formed in the shape of a ring. Then, as shown inFIG. 10B, based on theconnection portion112d,thesheet metal112′ is folded to overlap each other and surfaces facing each other are mutually bonded by soldering or welding (FIG. 12C), thereby obtaining thefirst lead frame110 having theheat transfer unit112.
• As shown inFIG. 11A, thesecond lead frame120 is disposed opposite to thefirst lead frame110 with a predetermined interval, and thepackage body130 where the lead frames110 and120 are inserted by insertion molding or injection molding is formed (FIG. 12D). In this case, by theconcave portion132 of thepackage body130, portions of the top and bottom112aand112bof theheat transfer unit112 and thesecond lead frame120 are exposed. Also, the ring-shapedportion130bis formed in the inner wall of thegroove140 of theheat transfer unit112, and the ring-shapedportion130bhas theaperture114 exposing the bottom112bfor stably mounting theLED chip105.
• As shown inFIG. 11B, theLED chip105 is mounted on theaperture114 of the ring-shapedportion130b,and bonding wires W required for an electric connection is formed (FIG. 12E) According to requirements, a Zener diode may be mounted on an outer side of the ring-shapedportion130b.Thephosphor layer160 coating theLED chip105 is formed on theaperture114 of the ring-shapedportion130b(FIG. 12F). To cover thephosphor layer160, the light-transmittingencapsulation portion180 is formed on theconcave portion132 of the package body130 (FIG. 12G). The light-transmittingencapsulation portion180 may be formed of a light-transmitting resin containing one or more of phosphors and a light scattering material.
• FIGS. 13 to 17 are cross-sectional views illustrating LED packages according to various embodiments of the present invention.
• Referring toFIG. 13, anLED package400 may include anadditional lens401 mounted on the light-transmittingencapsulation portion180. Thelens401 may have various shapes such as a hemisphere, a dome, and an oval. As a material of thelens401, there are used a light-transmitting polymer or resin such as a polycarbonate, a polymethylmethacrylate (PMMA), a silicone resin and an epoxy resin. Thelens401 maybe filled with a color conversion material such as a light scattering material and phosphors.
• Referring toFIG. 14, in anLED package500, a top surface of aphosphor layer560 may have a profile of a concave lens. When the top surface of thephosphor layer560 has the profile of the concave lens, a height of the top surface (a minimum height) of thephosphor layer560 may be from 0.1 to 0.3 mm from a top surface of theLED chip105. With respect to this, when the top surface of thephosphor layer560 has a profile of a convex lens (refer toFIG. 4), a height of the top surface of the phosphor layer160 (a maximum height) may be from 0.2 to 0.8 mm from the top surface of theLED chip105.
• Referring toFIG. 15, in anLED package600, a light-transmittingencapsulation portion680 itself has a lens shape. This corresponds to that the light-transmittingencapsulation portion180 are perfectly integrated to thelens401 of an identical material. The light-transmittingencapsulation portion680 may be filled with one or more of a light scattering material and phosphors.
• Referring toFIG. 16, in anLED package700, theLED chip105 is connected to lead frames having a different polarity from each other by two bonding wires W1 and W2. For example, an n-electrode and a p-electrode (not shown) formed on a top surface of theLED chip105 having a vertical structure may be connected to theheat transfer unit112 of thefirst lead frame110 and thesecond lead frame120 by the two bonding wires W1 and W2, respectively.
• Referring toFIG. 17, anadditional submount801 is interposed between anLED chip105′ and the top112aof theheat transfer unit112. An electrode pattern is formed on thesubmount801 and electrically connected to theLED chip105′ that is a flip chip bonded to the electrode pattern. Electrode patterns (not shown) on both ends of thesubmount801 may be electrically connected to connection portions of the lead frames of corresponding polarities via the bonding wires W1 and W2. Thesubmount801 maybe formed of a silicone semiconductor.
• As described above, according to an exemplary embodiment of the present invention, there is provided an LED package with high color uniformity according to far-field beam distribution, less light loss, and excellent heat emission characteristics. Also, a profile of a phosphor layer is formed of a lens, thereby adjusting light intensity and far-field beam distribution.
• While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (17)

1. A light emitting diode (LED) package comprising:

an LED chip;

a first lead frame having a heat transfer unit with a top where a groove for stably mounting the LED chip is formed;

a second lead frame disposed separately from the first lead frame;

a package body having a concave portion encapsulating a portion of the heat transfer unit and the second lead frame but exposing a portion of the top of the heat transfer unit and a portion of the lead frame, and a ring-shaped portion extended in a ring shape along an inner wall of the groove of the heat transfer unit and forming an aperture in a center thereof; and

a phosphor layer formed on the aperture of the ring-shaped portion and applied to the LED chip,

wherein the LED chip is disposed in the inside of the aperture of the ring-shape portion.

2. The LED package ofclaim 1, wherein the heat transfer unit is formed by folding a sheet metal two times or more, the sheet metal with a top having a hole to form the groove of the heat transfer unit.

3. The LED package ofclaim 2, wherein the top of the folded sheet metal has a ring-shape since an incised portion connected to the hole is formed thereon.

4. The LED package ofclaim 1, wherein the heat transfer unit is formed of a sheet metal lamination body where two or more sheet metals are laminated, and

an uppermost sheet metal of the sheet metal lamination body has a hole to form the groove of the heat transfer unit.

5. The LED package ofclaim 4, wherein the uppermost sheet metal has a ring shape since an incised portion connected to the hole is formed thereon.

6. The LED package ofclaim 1, wherein the heat transfer unit is formed of a single structure of a sheet metal consecutively extended in a thickness direction, and

the sheet metal has different thicknesses in an inner area and an outer area of the groove of the heat transfer unit.

7. The LED package ofclaim 1, wherein at least portion of a bottom of the heat transfer unit is exposed from a bottom of the package body.

8. The LED package ofclaim 1, wherein an inner wall of the ring-shaped portion is slant in such a way that the aperture has a top broader than a bottom thereof.

9. The LED package ofclaim 1, wherein a height of the aperture of the ring-shaped portion is 0.1 to 0.7 mm, and

a horizontal distance between the inner wall of the ring-shaped portion and the LED chip is from 0.2 to 0.5 mm.

10. The LED package ofclaim 1, further comprising a light-transmitting encapsulation portion formed in the concave portion of the package body and covering a top surface of the phosphor layer.

11. The LED package ofclaim 10, wherein the light-transmitting encapsulation portion contains a light diffuser.

12. The LED package ofclaim 10, wherein the light-transmitting encapsulation portion contains phosphors.

13. The LED package ofclaim 10, further comprising a lens mounted on the light-transmitting encapsulation portion.

14. The LED package ofclaim 10, wherein the light-transmitting encapsulation portion is formed in the shape of a lens.

15. The LED package ofclaim 1, wherein the top surface of the phosphor layer has a shape of one of a convex lens and a concave lens.

16. The LED package ofclaim 1, further comprising a submount mounted on a bottom of groove and having electrode patterns,

wherein the LED chip is mounted on the submount and electrically connected to the electrode patterns, and

the electrode patterns of the submount are electrically connected to the lead frame by bonding wires.

17. The LED package ofclaim 1, wherein a hole for indicating a polarity is formed on one of external terminals of the first and second lead frames exposed from the package body.

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